Improvement in clamp-screw for calipers



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ya@ Y lm PKmLITHOGRAPMER, WASHINGTON. D. C.

DANIEL WRIGHT, JR., OF VVALTI-IAM', MASSACHUSETTS.

Letters Patent No. 94,266, dated August 31, 1869.

IMPROVEMENT IN CLAMP-SCREW FCR CALIPERS, 8cc.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern Be it known that I, DANIEL WRIGHT, Jr., ofWaltham, in the county of Middlesex, and State of Massachusettsfhaveinvented a new and useful Improvement on Screws; and I do hereby declarethat the Vfollowing; is a full-and exact description thereof', referencebeing had to the annexed drawing, making a part of this specification,in which- Figure l shows the nut and screw, as applied to a commoncaliper;

Figure 2 is a side view of the clamp;

Figure 3 is a longitudinal section of same; and- Figure 4 is a bottomview of iig. 2.

To enable others skilled in the art to make and use my invention, I willproceed to describe its construction and operation.

To give an idea of my invention, I will describe the same as used on atool called calipers, for measuring outside diameters, and thicknessesof shafts, bars, plates, 85o., or as used on a pair of dividers, forlaying out diierent sizes' of circles, curves, Sto.

In using the above-named tools, it frequently happens that the artisanhas at one time to take a very small measure, say, for example,one-eighth to onefourth of an inch, and, immediately after, he may haveoccasion to take a pretty large measure, say, for example, ive to sixinches, which difference necessitates the screwing out and in ofthehandle or nut (as commonly used) al great number of revolutions, as thescrew o is, in suc-h a case, of a very tine pitch. This repeated turningot the handle or nut is very annoy.- ing,'takes a long time, and isgreatly complained of by artisans having occasion to use similar tools.

T01 obv'iate this diiiculty, l construct my nut or handle'D as beingsplit in its lower or tapped end, D, where the screw plays, andyconnected together at its upper end by means of loops or springs, D'D', as shown in ligs. 1, 2, and 3, which make ahandle for the purpose ofturning the same on the screw.

The handle or clamp D, when 1n its natural 'position, plays entirelyfree over the screw c, and the calipers or similar tool may therefore heopen or shut; at

pleasiue, without turning the handle; but by simply pushing this clampor handle into the conical recess, or conical ring E, is the toolsecurely locked by means of the pressure outward from the spring B, onthe conical recess, which thereby crowds together the jaws D" D (fig. 3)over the screw, and makes the'handle similar to a solid nut. l

Should the tool again be required for a larger or smaller measure, thepressure together of the jaws D D may instantly be relieved by means ofpressing together' of the legs of the tool over F, (fig. 1,) when thejaws, D D" open, allowing them to play entirely free over the screw o,till such a place that is convenient to the measure to beitaken, when,by only pushing the nut or handle into the conical ring or socket, thetool is instantly locked, and the handle changed into a solid nut,having all the advantages of a common nut, withnone of itsdisadvantages.

Havingthus described the nature and construction of my-invention,

I wish to secure by `Letters Patent, and

l. A handle or nut, made in two parts, connected with a spring, andtapped for the reception of a screw, for the purpose set forth. f

2. The conical end D of the divided nut D, in combination with thehollow conical washer E, or the conically-shaped recess in the partoperated upon, substautially as shown and described.

DANIEL WRIGHT, JR.

Witnesses:

ALBAN G. ANDRS, A. LnSTEvENS.

